#include "common.h"
#include "global_config.h"

/* Global resources */
rt_mq_t g_msg_queue = RT_NULL;
rt_mutex_t g_data_mutex = RT_NULL;
rt_event_t g_system_event = RT_NULL;

static uint16_t g_seq_num = 0;


/* CRC16 table for MODBUS */
static const uint16_t crc16_table[256] = {
    0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241,
    0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440,
    0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40,
    0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841,
    0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40,
    0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41,
    0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641,
    0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040,
    0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240,
    0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441,
    0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41,
    0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840,
    0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41,
    0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40,
    0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640,
    0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041,
    0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240,
    0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441,
    0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41,
    0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840,
    0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41,
    0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40,
    0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640,
    0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041,
    0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241,
    0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440,
    0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40,
    0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841,
    0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40,
    0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41,
    0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641,
    0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040
};

rt_err_t common_init(void)
{
    /* Create message queue */
    g_msg_queue = rt_mq_create("msg_queue", 
                              sizeof(message_t), 
                              32, 
                              RT_IPC_FLAG_FIFO);
    if (g_msg_queue == RT_NULL) {
        LOG_E("Failed to create message queue\n");
        return ERR_MEM;
    }
    
    /* Create data mutex */
    g_data_mutex = rt_mutex_create("data_mutex", RT_IPC_FLAG_FIFO);
    if (g_data_mutex == RT_NULL) {
        LOG_E("Failed to create data mutex\n");
        rt_mq_delete(g_msg_queue);
        return ERR_MEM;
    }
    
    /* Create system event */
    g_system_event = rt_event_create("system_event", RT_IPC_FLAG_FIFO);
    if (g_system_event == RT_NULL) {
        LOG_E("Failed to create system event\n");
        rt_mq_delete(g_msg_queue);
        rt_mutex_delete(g_data_mutex);
        return ERR_MEM;
    }
    
    LOG_I("Common resources initialized successfully\n");
    return RT_OK;
}

rt_err_t send_message(module_id_t dst, uint32_t type, void *data, uint16_t len)
{
    message_t msg;
    
    if (dst >= MODULE_MAX) {
        return ERR_PARAM;
    }
    
    msg.src_module = MODULE_MAIN;
    msg.dst_module = dst;
    msg.msg_type = type;
    msg.timestamp = rt_tick_get();
    msg.data = data;
    msg.data_len = len;
    msg.seq_num = g_seq_num++;
    
    rt_err_t result = rt_mq_send(g_msg_queue, &msg, sizeof(msg));
    if (result != RT_OK) {
        LOG_E("Failed to send message to module %d, type: 0x%08X\n", dst, type);
        return ERR_IO;
    }
    
    return RT_OK;
}

rt_err_t broadcast_message(uint32_t type, void *data, uint16_t len)
{
    message_t msg;
    
    msg.src_module = MODULE_MAIN;
    msg.msg_type = type;
    msg.timestamp = rt_tick_get();
    msg.data = data;
    msg.data_len = len;
    msg.seq_num = g_seq_num++;
    
    /* Broadcast to all modules except main */
    for (module_id_t dst = MODULE_IO; dst < MODULE_MAX; dst++) {
        msg.dst_module = dst;
        rt_mq_send(g_msg_queue, &msg, sizeof(msg));
    }
    
    return RT_OK;
}

uint32_t get_timestamp(void)
{
    return rt_tick_get();
}

float linear_calibration(float raw, float k, float b)
{
    return k * raw + b;
}

float table_calibration(float raw, cal_point_t *table, uint8_t size)
{
    if (size < 2 || table == RT_NULL) {
        return raw;
    }
    
    /* Check if raw value is below first point */
    if (raw <= table[0].measured) {
        return table[0].standard;
    }
    
    /* Check if raw value is above last point */
    if (raw >= table[size-1].measured) {
        return table[size-1].standard;
    }
    
    /* Find the segment and interpolate */
    for (uint8_t i = 0; i < size - 1; i++) {
        if (raw >= table[i].measured && raw <= table[i+1].measured) {
            float ratio = (raw - table[i].measured) / 
                         (table[i+1].measured - table[i].measured);
            return table[i].standard + 
                   ratio * (table[i+1].standard - table[i].standard);
        }
    }
    
    return raw;
}

uint16_t calculate_crc16(uint8_t *data, uint16_t len)
{
    uint16_t crc = 0xFFFF;
    
    if (data == RT_NULL) {
        return crc;
    }
    
    for (uint16_t i = 0; i < len; i++) {
        crc = (crc >> 8) ^ crc16_table[(crc ^ data[i]) & 0xFF];
    }
    
    return crc;
}
